The 'I Will Always Love You' singer appeared to be on the verge of a comeback prior to her death, having co-starred in the music-themed film Sparkle with Sparks.

In an interview with The New York Daily News, Sparks recalled the shock she felt after learning of Houston's death.

"I was about to go change into my dress [for a Grammys event] and there was a knock on the door… It was my publicist, who told me, 'Whitney's gone.' I said, 'What do you mean? Did she leave the hotel already?' And she said, 'No - Whitney's passed'," Sparks recalled.

She continued: "I was so shocked I couldn't even move. I didn't know what to do. I didn't go to the Grammys [on Sunday], and I canceled a lot of appearances after that. I didn't want people asking me about her. I just didn't think it was my place to say anything.

"I ended up being secluded; I cut myself off for a couple of months. I was just crying, I was so devastated. And I'd only known her for the two months we worked together. I can't imagine how her family and friends who had known her for a long time felt. She was very loved."

Sparks went on to reflect on the impact Houston had on her life and career.

"I was somebody who had listened to Whitney's music and tried to emulate her," she explained. "So to get to work with her in this intimate setting [in Sparkle], to do scenes where we were yelling at each other, and then holding hands with her... I just loved her."